18255600 ÷ 991 
The aim is to understand the frequency of 991 in 18255600.

On to step 1:
991 goes into 1 0 times with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 991

Moving on to step 2:
991 can be fit into 18 0 times, resulting in a remainder of 18.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 18, we end up with 18.
Append the next digit (2) from the dividend to 18 and continue with: 182 / 991

Going ahead to step 3:
182 divided by 991 is 0 with a remainder of 182.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 182 and we're left with 182.
Fetch the next digit (5) from the dividend, attach it to 182 and continue: 1825 / 991

Advancing to step 4:
If we divide 1825 by 991, we get 1 and a remainder of 834.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 991 from 1825 leaves us with 834.
Include the next digit (5) from the dividend after 834, then repeat: 8345 / 991

Going ahead to step 5:
991 goes into 8345 8 times with a remainder of 417.
Put 8 as the next digit of the answer. 
Result so far: 18.0
Subtracting 7928 from 8345 leaves us with 417.
Grab the next digit (6) from the dividend, add it to 417, then carry on: 4176 / 991

Going ahead to step 6:
991 can be fit into 4176 4 times, resulting in a remainder of 212.
Put 4 as the next digit of the answer. 
Result so far: 184.0
If we take 3964 away from 4176, we end up with 212.
Take the next digit (0) from the dividend and append it to 212, then repeat: 2120 / 991

Step 7:
991 can be fit into 2120 2 times, resulting in a remainder of 138.
Record the quotient 2 as the next digit in the result. 
Result so far: 1842.0
Subtract 1982 from 2120 to get 138.
Bring next digit (0) of the dividend behind the 138 and repeat the process: 1380 / 991

Let's proceed to step 8:
991 goes into 1380 1 times with a remainder of 389.
Put 1 as the next digit of the answer. 
Result so far: 18421.0
Deduct 991 from 1380 and we're left with 389.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3890, and continue the process.

Advancing to step 9:
3890 divided by 991 is 3 with a remainder of 917.
Put 3 as the next digit of the answer. 
Result so far: 18421.3
If we take 2973 away from 3890, we end up with 917.
Since there are no more digits in the dividend, we add a zero to the remainder making it 9170, and continue the process.

Advancing to step 10:
If we divide 9170 by 991, we get 9 and a remainder of 251.
The number 9 becomes the next digit in our result. 
Result so far: 18421.39
Subtracting 8919 from 9170 leaves us with 251.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2510, and continue the process.

Let's proceed to step 11:
991 goes into 2510 2 times with a remainder of 528.
Record the quotient 2 as the next digit in the result. 
Result so far: 18421.392
Deduct 1982 from 2510 and we're left with 528.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5280, and continue the process.

Step 12:
5280 divided by 991 is 5 with a remainder of 325.
Use 5 as the next digit of our solution. 
Result so far: 18421.3925
Subtract 4955 from 5280 to get 325.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3250, and continue the process.

On to step 13:
991 can be fit into 3250 3 times, resulting in a remainder of 277.
Write down 3 as next digit of the result. 
Result so far: 18421.39253
Subtract 2973 from 3250 to get 277.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2770, and continue the process.

Step 14:
991 can be fit into 2770 2 times, resulting in a remainder of 788.
Record the quotient 2 as the next digit in the result. 
Result so far: 18421.392532
If we subtract 1982 from 2770, we get 788.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7880, and continue the process.

Going ahead to step 15:
991 goes into 7880 7 times with a remainder of 943.
The number 7 becomes the next digit in our result. 
Result so far: 18421.3925327
If we subtract 6937 from 7880, we get 943.
Since there are no more digits in the dividend, we add a zero to the remainder making it 9430, and continue the process.

Let's proceed to step 16:
The number 991 fits into 9430 9 times, leaving a remainder of 511.
Write down 9 as next digit of the result. 
Result so far: 18421.39253279
If we subtract 8919 from 9430, we get 511.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5110, and continue the process.

Our division results in 18421.39253279 with a remaining 5.11e-07.